Go toArchive
Browse byFacets
Bookbag ( 0 )
'membranes' in keywords
Results  14 Items
Sorted by   
Publication Year
2001 (1)
1985 (1)
1984 (2)
1982 (1)
1980 (1)
1978 (1)
1976 (1)
1975 (3)
1974 (2)
1972 (1)
1Author    Friederike Koenig, Wilhelm Menke, Hans Craubner, GeorgH. Schmid, Alfons RadunzRequires cookie*
 Title    Photochemically Active Chlorophyll-Containing Proteins from Chloroplasts and their Localization in the Thylakoid Membrane  
 Abstract    After solubilization of stroma-freed chloroplasts with deoxycholate, the lipids and the detergent used are separated from the proteins by gel filtration. In this way not denatured pigment-con-taining protein preparations were obtained. The particles in fraction 1 exhibited a molecular weight of 600 000 and contained an average of 25 chlorophyll molecules. The circular dichroism spectrum showed exciton splitting of the red band. The particles in fraction 2 contained 1 chloro-phyll molecule and exhibited a molecular weight of 110 000. The particles in fraction 3 also contained only 1 chlorophyll molecule and had a molecular weight of between 80 000 and 100 000. Pure preparations of fraction 1 only carried out the methylviologen M e h 1 e r reaction with the dichlorophenol indophenol/ascorbate couple as electron donor. Fraction 3 only reduced ferri-cyanide with diphenylcarbazide as an electron donor in the light. Fraction 2 exhibited both the photosystem I reaction and the photosystem II reaction. An antiserum to extracted fraction 1 does not inhibit electron transport in the intact lamellar system. The photoreduction of methylviologen is only inhibited after disruption of the thylakoids. The antiserum to fraction 2 inhibits the photo-reduction of methylviologen in the intact lamellar system. Consequently, one inhibition site for this photosystem I reaction must be located on the inner and another on the outer surface of the thylakoid membrane. In addition, antibodies to fraction 1 are specifically adsorbed onto the lamellar system without any effect on electron transport and without a concomitant agglutination. Antibodies to fraction 3 partially inhibit the photoreduction of ferricyanide with diphenylcarbazide as an electron donor in the intact lamellar system. Hence, the inhibition site of this system II reaction is located on the outer surface of the thylakoids. We have reason to believe that the inhibition sites not reacting are located in the partitions, which are not accessible to antibodies. 
  Reference    (Z. Naturforsch. 27b, 1225 [1972]; received July 5 1972) 
  Published    1972 
  Keywords    Chloroplasts, membranes, proteins, photosynthesis, antibodies 
  Similar Items    Find
 TEI-XML for    default:Reihe_B/27/ZNB-1972-27b-1225.pdf 
 Identifier    ZNB-1972-27b-1225 
 Volume    27 
2Author    Jeffrey Karan, SeymourSteven BrodyRequires cookie*
 Title    Chlorophyll a and Cytochrome c at a Heptane-Water Interface  
 Abstract    The surface pressure was measured as a function of area/molecule for chlorophyll a (Chi) and cytochrome c (Cyt) at a heptane-water interface. At a surface pressure of 6 dyn/cm the area per molecule of C h l(^ 6) = 1 1 3 ±6 Ä 2, for reduced Cyt c (red. Cyt) the A6 = 5000 ± 300 Ä 2 and for oxidized Cyt c (ox. Cyt) /3(6=4100 ± 250 A2. Cyt appears to denature at the interface. Irradiation results in a decrease of the for Chi to ^ 8 = 1 0 0 ± 5 Ä 2. There appears to be interaction between Chi and red. Cyt in a mixed film no interaction is observed between Chi and ox. Cyt. 
  Reference    (Z. Naturforsch. 29c, 506 [1974]; received June 14 1974) 
  Published    1974 
  Keywords    Chlorophyll, Cytochrome, Monolayers, Photosynthesis, Membranes 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/29/ZNC-1974-29c-0506.pdf 
 Identifier    ZNC-1974-29c-0506 
 Volume    29 
3Author    Hans GrulerRequires cookie*
 Title    Chemoelastic Effect of Membranes  
 Abstract    The elastic theory of a uniaxial membrane in an asymmetric environment predicts a spontaneous splay deformation. This spontaneous curvature of the membrane is discussed by the intrinsic splay of the membrane molecules (e. g. wedge shaped molecules) and their polar orientation. The chemoelastic effect is the polar orientation induced by the asymmetric environment in connection with the intrinsic splay. This effect is also discussed for polyelectrolytes where a small change of pH (~0.1) can lead to a spontaneous curvature of 104 cm-1. The actual shape of red blood cells can be explained by the spontaneous splay and a change in environment induces the change in shape of these cells. A model is proposed for two conical bodies swimming in a uniaxial membrane which interact with each other through elastic coupling. The force between the bodies can be either attractive or repulsive. As an example of this model clustering of proteins is discussed. 
  Reference    (Z. Naturforsch. 30c, 608—614 [1975]; received June 18 1975) 
  Published    1975 
  Keywords    Membrane, Elasticity, Erythrocyte, Enzyme Coupling 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/30/ZNC-1975-30c-0608.pdf 
 Identifier    ZNC-1975-30c-0608 
 Volume    30 
4Author    H.G L Coster, U. ZimmermannRequires cookie*
 Title    Transduction of Turgor Pressure by Cell Membrane Compression  
 Abstract    It is suggested that turgor pressure sensing in plant cells occurs via compression of the cell membranes; either at the plasmalemma where a pressure gradient exists, or the tonoplast due to the pressure developed inside the cell. Considerations of electro-mechanical forces in electrical breakdown of cells suggests that significant changes in the thickness of som e regions of the mem­ brane can indeed occur. It is readily envisaged how such changes in membrane thickness can be coupled to changes in active transport processes. 
  Reference    (Z. Naturforsch. 31c, 461 [1976]; received April 13 1976) 
  Published    1976 
  Keywords    Turgor, Membrane, Pressure, Compression, Osmoregulation 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/31/ZNC-1976-31c-0461.pdf 
 Identifier    ZNC-1976-31c-0461 
 Volume    31 
5Author    Hiroko Ito, K. Aran, RhodaElison Hirsch, SeymourSteven BrodyRequires cookie*
 Title    Stability and Regeneration of Rhodopsin Absorption Spectra at an Air-Water Interface  
 Abstract    Stability and regenerability of the absorption spectrum of CTAB solubilized rhodopsin at an air-water interface is studied. The spectral properties of rhodopsin films in the dark are stable more than 150 minutes. When rhodopsin is bleached (40 — 50%) and maintained in highly com­ pressed films recovery of the spectrum is observed. The recovery is 57% to 100% of the pigment present before irradiation. At low surface pressure or if the films are expanded after irradiation there is no observable recovery. 
  Reference    Z. Naturforsch. 33c, 317 (1978); received March 28 1978 
  Published    1978 
  Keywords    Vision, Rhodopsin, Monolayers, Membranes, Photobiology 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/33/ZNC-1978-33c-0317.pdf 
 Identifier    ZNC-1978-33c-0317 
 Volume    33 
6Author    Mario Suwalsky3, Carlos Schneider3, Fernando Villenab, Beryl Norrisb, HernanC. Árdenasb, Francisco Cuevasc, CarlosP. SotomayorcRequires cookie*
 Title    Dibucaine-Induced Modification of Sodium Transport in Toad Skin and of Model Membrane Structures  
 Abstract    The interaction of the local anesthetic dibucaine with the isolated toad skin and membrane models is described. The latter consisted of human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), large unilamellar vesicles (LUV) of dimyristoylphosphati-dylcholine (DMPC) and phospholipid multilayers built-up of DMPC and dimyristoylphos-phatidylethanolamine (D M PE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. Results indicate a significant decrease in the potential difference (PD) and in the short-circuit current (Isc) after the application of dibucaine in toad skin, which may be interpreted as reflecting inhibition of the active transport of ions. This finding might be explained on the basis of the results ob­ tained from fluorescence spectroscopy and X-ray diffraction studies on membrane models. In fact, dibucaine induced structural perturbations in IUM, DMPC LUV and phospholipid multilayers. Scanning electron microscopy revealed that dibucaine induced erythrocyte sto-matocytosis. According to the bilayer couple hypothesis an echinocytic type of shape change would have been expected given the preferential interaction of dibucaine with DMPC. Al­ though it is still premature to define the molecular mechanism of action of dibucaine, the experimental results confirm the important role played by the phospholipid bilayers in the association of the anesthetic with cell membranes. 
  Reference    Z. Naturforsch. 56c, 614 (2001); received January 29/March 8 2001 
  Published    2001 
  Keywords    Local Anesthetic, Dibucaine, Membrane 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0614.pdf 
 Identifier    ZNC-2001-56c-0614 
 Volume    56 
7Author    N. Yckowski, S. S. BrodyRequires cookie*
 Title    Interactions of Monomolecular Films of Retinal at Alkaline pH  
 Abstract    The surface properties of mixed monomolecular films of retinal and phospholipids were studied at a nitrogen/water interface. The subphase was glycine buffer pH 10.5 with an ionic strength of 0.1. Monomolecular films of retinal in the presence of amino acids were also measured. The area per molecule, at a surface pressure of 10 dyn/cm, A 10, in the dark for 9-cis retinal and 11-ci's retinal are 42 A 2 and 47 A 2, respectively. After irradiation A 10 for 9-cis retinal and 11-cts retinal dcerease to 40 A 2 and 43 A2, respectively. The surface potentials, AV, at a surface pressure of 10 dyn/cm, in the dark for 9-cis retinal and 11-cis retinal are 470 mV and 445 mV, respectively. After irradiation, AV for 9-cis retinal decreases to 435 mV and 11-cis retinal increases to 490 mV. Interaction was observed between retinal and phospholipids and amino acids. The A 10 and AV 10 of mixed films of retinal and phospholipid were measured as a function of the mole fraction of phospholipid. Maximum interaction is observed at mole ratios of; phosphatidylserine/9-ct's = 1; phosphatidylethanolamine/9-m = 2, phosphatidylserine/ll-cis = 3; phosphatidylethanolamine/ H-CJ5 = 3. It is shown that mixing and interaction between phosphatidylethanolamine and retinal is spontaneous. The A 10 and A V 10 of films of retinal were measured as a function of the molar concentration of amino acid in the subphase. The nature of the interaction between retinal and phospholipid and amino acid are discussed. 
  Reference    (Z. Naturforsch. 29c, 327 [1974]; received April 1 1974) 
  Published    1974 
  Keywords    ) Vision, Retinal, Monolayers, Membranes, Model systems 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/29/ZNC-1974-29c-0327.pdf 
 Identifier    ZNC-1974-29c-0327 
 Volume    29 
8Author    N. Puppala, S. S. BrodyRequires cookie*
 Title    Interactions between Retinal and Phospholipids in Monomolecular Films at Acid pH  
 Abstract    The surface properties of mixed monomolecular films of retinal and phospholipids (p. lipids) are measured as a function of mole fraction at a nitrogen-water interface. An acid pH of 6.0 is maintained in the aqueous phase. Before irradiation the surface potential A V for 9-cis retinal, 11-cis retinal, phosphatidyl serine (PS) and phosphatidyl ethanolamine (PE), at j t = 12 dyn/cm, are 490 mV, 645 mV, 548 mV and 375 mV, respectively. Before irradiation, A 0 for 9-cis and 11-ds are 58 Ä2 and 48 A2, respectively. Experimentally measured isotherms are compared with theo­ retically calculated isotherms. In case of mixed films of retinal and PS the experimental isotherms are greater than theoretical, while mixed films of retinal and PE are smaller than theoretical. A maximum value for the difference between theoretical and experimental areas are obtained at (retinal) / (p. lipid) = 0 .1 . Retinal and p. lipid do not appear to form a Schiff base, charge transfer or any other type of complex at pH 6. A eutectic type mixture between retinal and p. lipid may occur on the surface. A light induced change in A V of —130 mV is observed in the case of 11-cis and PE. The significance of these findings with respect to visual excitation is considered. 
  Reference    (Z. Naturforsch. 30c, 478—483 [1975]; received October 4 1973/October 21 1974) 
  Published    1975 
  Keywords    ) Vision, Retinal, Monolayers, Photobiology, Membranes 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/30/ZNC-1975-30c-0478.pdf 
 Identifier    ZNC-1975-30c-0478 
 Volume    30 
9Author    HansW. Ulrich, EltzienRequires cookie*
 Title    Lysolecithin Induced Membrane Alterations in Thymocytes Effects of Lysophosphatides Possessing A djuvant and Immuno-Suppressive Activities on Cell Agglutination by Concanavalin A  
 Abstract    The effects of lysolecithin and of 2 synthetic ether-desoxy lysolecithin analogs, containing alkyl residues of 16 or 12 carbon atoms, on the agglutination kinetics of calf and rabbit thymocytes by concanavalin A (Con A) were investigated. Unlike the natural lysolecithin, these synthetic analogs are resistant to metabolism by membrane associated enzymes. It was found that pretreat­ ment of thymocytes with lysolecithin or with the C16-analog leads to slightly increased agglutination rates. The C12-analog, in contrast, significantly inhibits thymocyte agglutination by Con A. More­ over, a comparison of these results with lysophosphatide effects on the agglutinability of erythro­ cytes of various species revealed that the inhibitory effect of the short-chain phosphatide is rather specific for thymocytes. The finding that long-and short-chain lysophosphatides, which have pre­ viously been shown to react as adjuvants or immunosuppressants, respectively, induce adserve alterations in thymocyte membranes indicates that these substances may affect the immune response by changing the membrane properties of immune competent cells. Concerning the nature of these membrane alterations it was shown that lysolecithin did not affect the number of Con A receptors per cell nor the affinity of lectin binding. It is therefore concluded that the lysophosphatide in­ duced alterations of Con A agglutinability can not be caused by an uncovering or covering of lectin-receptors. 
  Reference    (Z. Naturforsch. 30c, 785 [1975]; received June 30 1975) 
  Published    1975 
  Keywords    Thymocytes, Membranes, Lysolecithin, Concanavalin A, Agglutination 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/30/ZNC-1975-30c-0785.pdf 
 Identifier    ZNC-1975-30c-0785 
 Volume    30 
10Author    Renate Meier, W. Erner Reisser, Wolfgang Wiessner, Marcelle Lefort-TranRequires cookie*
 Abstract    Measurements of particle densities on the two freeze-fracture faces of digestive and perialgal vacuole mem­ branes in green and aposym biotic Paramecium bursaria Ehrbg. show distinct differences between the P-faces of both m em brane types. The distribution of particle den­ sities is more homogenous on the P-faces of perialgal vacuole membranes than on the P-faces o f digestive vacuole membranes. Possibly homogeneity among peri­ algal vacuole membranes reflects the stability o f perialgal vacuoles during their life cycle. Perhaps lysosomes cannot fuse with them. 
  Reference    Z. Naturforsch. 35c, 1107—1110 (1980); received October 28 1980 
  Published    1980 
  Keywords    Paramecium bursaria, Chlorella sp, Symbiosis, Membranes, Freeze-Fracture 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/35/ZNC-1980-35c-1107_n.pdf 
 Identifier    ZNC-1980-35c-1107_n 
 Volume    35 
11Author    M. Suwalsky, E. KnightRequires cookie*
 Title    X-Ray Studies on Phospholipid Bilayers. II. Polymorphic Forms of Dipalmitoyl Phosphatidylethanolamine  
 Abstract    Oriented films and powder samples of the phospholipid L-x-dipalmitoyl phosphatidylethanol­ amine (DPPE) were studied by X-ray fiber diffraction techniques. The specimens were photographed under a complete range of hydration at room temperature. Two polymorphic forms were found. One of them was present in oriented films. It showed a close packing of DPPE molecules lying parallel to the normal to the bilayer plane. The other form, observed in the powder samples, had the molecules tilted by about 25°. Both forms were characterized by their unit cell dimensions, space groups, molecular conformations and packing arrangements. 
  Reference    Z. Naturforsch. 37c, 1157—1160 (1982); received June 2/August 16 1982 
  Published    1982 
  Keywords    Phospholipid, Bilayers, X-Ray Diffraction, Dipalmitoyl Phosphatidylethanolamine, Membrane 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/37/ZNC-1982-37c-1157.pdf 
 Identifier    ZNC-1982-37c-1157 
 Volume    37 
12Author    Gottfried Küppers, Karl-Josef Diederich, Ulrich ZimRequires cookie*
 Title    Cell Fusion by Simulated Atmospheric Discharges: Further Support for the Hypothesis of Involvement of Electrofusion in Evolution  
 Abstract    Electrofusion of mesophyll cell protoplasts of Avena sativa was induced by simulated atmospheric discharges. It is shown both experimentally and theoretically that the potential differences which occur at quite long distances from the point of lightning stroke are large enough to induce fusion. Besides electromagnetic waves which are emitted during lightning (G. Küppers and U. Zimmermann, FEBS Lett. 164, 323 (1983)) cell fusion may have also occurred directly by means of the voltage built-up on the earth during evolution in response to a lightning stroke. 
  Reference    Z. Naturforsch. 39c, 973—980 (1984); received June 5 1984 
  Published    1984 
  Keywords    Electrofusion, Atmospheric Discharge, Step Voltage, Evolution, Membrane, Protoplasts 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0973.pdf 
 Identifier    ZNC-1984-39c-0973 
 Volume    39 
13Author    Akira Taketo, Yoriko TaketoRequires cookie*
 Title    Effects of Membrane-Acting Drugs and Aerobiosis on Production of Streptolysin S and Nuclease in Hemolytic Streptococci  
 Abstract    Yield of streptolysin S (SLS) in streptococcal culture was considerably reduced by procaine, dibucaine, atropine or chlorpromazine at concentrations which scarecely affected production of an extracellular nuclease as well as the bacterial growth. Cerulenin was also inhibitory to SLS formation, but its effect was more pronounced on the nuclease production. By aerobiosis, amount of SLS produced into culture supernatant was increased significantly, whereas yield of the nuclease was rather unaffected. 
  Reference    Z. Naturforsch. 39c, 1128—1131 (1984); received August 14 1984 
  Published    1984 
  Keywords    Streptolysin S, Nuclease, Membrane, Aerobiosis, Streptococci 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-1128.pdf 
 Identifier    ZNC-1984-39c-1128 
 Volume    39 
14Author    EugeneL. Barsky, FainaD. Kamilova, VitalyD. Samuilov, IcrobiologyRequires cookie*
 Title    Do Cyanobacteria Contain a Membrane Bound Cysteine Oxidase? Department o f Cell Physiology and Im m unology* and Department o f M  
 Abstract    The oxidation o f cysteine with 0 2 is facilitated by isolated membranes o f the cyanobacteria A nacystis nidulans and Anabaena variabilis, and further stimulated by Fe3+. This reaction accelerates with increasing the pH value and is suppressed by cyanide, benzylhydroxamate, hydroxylamine, but not azide. The agents m entioned inhibited the respiration o f the m embranes with ascorbate and N ,N ,N',N'-tetram ethyl-p-phenylenediam ine (TM PD) effectively, but did not influence their nonenzym ic oxidation. It is inferred that ascorbate in com bination with TM PD is oxidized via membrane oxidases. Cysteine oxidation apparently proceeds non-enzym atically and is catalyzed by the cations o f heavy metals. 
  Reference    Z. Naturforsch. 40c, 176 (1985); received October 2/D ecem ber 18 1984 
  Published    1985 
  Keywords    Cysteine Oxidation, Oxygen Uptake, Heavy Metal Cations, Membranes, Cyanobacteria 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/40/ZNC-1985-40c-0176.pdf 
 Identifier    ZNC-1985-40c-0176 
 Volume    40